The invention generally relates to a wellhead assembly, and a prefabricated article of manufacture for use therewith, as well as a method for installing the prefabricated article of manufacture in the wellhead assembly. More particularly, the invention relates to a wellhead assembly having a control line associated therewith, the control line running to a structure within the well for effecting hydraulic, pneumatic, or electrical actuation thereof. The control line is not concentric with the tubing string, and is disposed exteriorly thereof, so that the control line may be removed without disturbing the well string. A sleeve is provided surrounding the control line and a section of the upper well string, concentric with the well string but axially spaced therefrom a sufficient distance to allow passage of the control line therebetween. A seal is provided between the lower wellhead assembly and the sleeve, whereby the well is kept under control at all times, eliminating an open hole condition, yet the well string is reciprocal with respect to the wellhead assembly and the sleeve. The sleeve also provides protection for the control line, and provides for positive passage and guidance of the control line down the well into its proper position.
According to the present invention, a tubing hanger mandrel, tubing hanger body having a control line port therein, an upper tubing string section, and the sleeve may be prefabricated as a single article of manufacture (even though the component pieces thereof may be releasably connected), and installed as a single unit in the field. This eliminates the otherwise costly and tedious field assembly that would be necessary, and greatly simplifies the installation procedure. A split coupling support assembly may be provided associated with the prefabricated article of manufacture to facilitate the installation thereof in the wellhead assembly, the coupling support only being utilized in the installation procedure, and being removed before actual connection is made between the lower wellhead assembly and the tubing bonnet.
According to one aspect of the present invention, a wellhead assembly is provided comprising an upper wellhead assembly including a tubing string section, a control line, and means for mounting said tubing string section and for mounting said control line exterior of said tubing string section, a lower wellhead assembly including means defining a bore therethrough through which said tubing string section and said control line pass, a sleeve operatively connected to said upper wellhead assembly and extending into said bore and surrounding said control line and said tubing string section, and means for forming a seal between said lower wellhead assembly and said sleeve.
According to another aspect of the present invention, an article of manufacture for use in the wellhead assembly is provided, said article comprising a tubing hanger mandrel, a tubing hanger body operatively connected to said tubing hanger mandrel and adapted to be connected to a tubing bonnet of a wellhead assembly, means defining a control line receiving port and said tubing hanger body, said port adapted to receive a control line therein to pass through a lower wellhead assembly, a tubing string section operatively connected to said tubing hanger mandrel and adapted to extend past the tubing hanger body into and through a lower wellhead assembly, and a sleeve operatively connected to said tubing hanger body and concentric with, but axially spaced from, said tubing string section, said sleeve adapted to extend into a lower wellhead assembly and form a seal therewith. A method of assembling a wellhead assembly is also provided, utilizing the article of manufacture according to the present invention, the method comprising the steps of running a control line through the control line receiving port of the tubing hanger in supporting the control line in the port, inserting the tubing well string section and sleeve of the article of manufacture partially into the lower wellhead assembly while supporting the tubing hanger body spaced from the lower wellhead assembly by disposing a coupling support assembly between the lower wellhead assembly and the tubing hanger body surrounding the sleeve, operatively connecting the tubing hanger body to the tubing bonnet, while the tubing hanger body is supported spaced from the lower wellhead assembly, removing the coupling support assembly from between the lower wellhead assembly and the tubing hanger body, and lowering the tubing bonnet into sealing engagement with the lower wellhead assembly.
It is the primary object of the present invention to provide a wellhead assembly, wherein the tubing string is reciprocal with respect to the assembly, while a seal is still maintained to keep the well under control and eliminate an open-hole condition, to protect a control line operatively associated with the wellhead assembly, while providing positive passage and guidance therefor, and allowing removal of the control line without consequent removal of the tubing string; to provide an article of manufacture utilizable in the wellhead assembly that eliminates expensive and time-consuming field installation and simplifies field installation procedures; and to provide a simplified method of field installation of a wellhead assembly having a control line associated therewith. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.